Need some Mechanical help

[gen3usa]

First off thank you all for your help....scenario below...
Truck, 1985 Silverado 454 74k original miles

Driving home from work, when i let off the throttle to coast up the ramp, heard a back fire, then another and then engine died, I pulled over and pedaled the gas a few times and it ran rough, while manipulating the pedal to get her home, pulled up to house and it died again.

Yesterday went out and fired up like normal and drove around for about 20-30 min, then it started doing it again, as long as i keep my foot on the pedal some it stays started but if i take my foot off it runs rough and will die.

Any thoughts? Fuel pump was initial thought....help is needed as i want to have the beast representing daily on the road as the best truck made.